While it is very natural to refer to the latest Pleistocene these mastodons which lie so near the surface, it must not be concluded with too much assurance that they do belong to the Late Wisconsin. The discovery of horse-teeth in the Navesink Hills and of Megatherium at Long Branch shows that the older Pleistocene deposits are present in this region.
11. Navesink Hills, Monmouth County.—In 1869 (Jour. Acad. Nat. Sci. Phila., vol. VII, p. 261), Leidy reported that remains of the mastodon had been found in this region, associated with a vertebra and some teeth of a fossil horse. This was based on Mitchill’s statement (Cat. Organ. Remains, p. 7) that he had a part of a tibia of a mastodon.
12. Manasquan Inlet, Monmouth County.—In 1882 (Amer. Jour. Sci., vol. XXIV, p. 294), Lockwood stated that he had known of a tusk and some other bones of a mastodon which had been uncovered by sea-waves in a storm about 15 miles south of Long Branch. In another place (Pop. Sci. Monthly, vol. XXII, p. 344) he spoke of a tusk which had been thus unearthed in Monmouth County. The place was evidently north of Manasquan Inlet.
Salisbury and Knapp (Geol. Surv. New Jersey, vol. VIII) describe the region along the coast from Manasquan River to Long Branch as presenting Cape May deposits at elevations below 40 or 45 feet, while modern beach deposits occupy some areas below this level. It seems, however that some of these supposed Recent materials contain extinct vertebrates and are older than they appear to be.
13. Verona, Essex County.—George H. Cook (Geol. New Jersey, 1868, p. 741) stated that a very perfect tooth of a mastodon had been picked up near Verona. This town is on Peckman Brook, and in the valley of this stream there is some stratified drift which is referred to the Wisconsin. Too little is known about the history of the tooth to enable one to determine with confidence its geological age.
14. Rockport, Warren County (Schooley’s Mountain).—In 1828 (Amer. Jour. Sci., vol. XIV, p. 188), Thomas P. Stewart reported the discovery of what he called a mammoth on Schooley’s Mountain. It was met with in 1827, in excavating the Morris Canal. The locality must therefore be west of Musconetcong River and probably not far from Rockport. The bones lay at a depth of about 3 feet. The animal was evidently a mastodon. A tooth, a lower last molar, measured 3.5 inches in width and 7 inches in length. The enamel was well preserved. Other bones were found.
15. Hackettstown, Warren County.—In the fourth volume of the Proceedings of the American Philosophical Society, 1844, on pages 118 to 121, there is an account, by J. B. Maxwell, of the discovery of the remains of 5 mastodons near Hackettstown, about halfway on the road to Vienna. In this vicinity is a ridge of gneiss which runs in a northeast-and-southwest direction. On this ridge is a pond-like depression about 40 yards in length by 25 yards in width, which at one time was a marsh. After it was drained the owner began digging in it and discovered the mastodon skeletons. They are described as consisting of one animal pretty large, three of smaller size, and one a calf. From these were obtained a skeleton which became the property of Harvard University and has since been known as the Cambridge skeleton. It is described by Warren in both editions of his “Monograph on the Mastodon.” Jackson (Proc. Bost. Soc. Nat. Hist., vol. II, p. 60) described these skeletons. A lower jaw of a young individual had two alveoli for lower tusks, 0.75 inch in diameter.
Asa Gray (Proc. Bost. Soc. Nat. Hist., vol. II, 1848, p. 92) examined wood which had been taken in the place occupied by the stomach of the skeleton referred to. He found no differences between it and that of the common hemlock spruce. While Gray speaks of this mastodon as being found on Schooley’s Mountain, he evidently meant the ones found at Hackettstown.
According to Maxwell’s account there was at the surface 6 inches of vegetable deposit; below this was found about 6 inches of whitish sand; while below this came a bed of pure muck from 4 to 6 feet in depth. In this were buried the mastodon bones.
Lyell (Second Visit to U. S., ed. 3, vol. II, p. 363) mentions the skeletons found at Hackettstown. Between the ribs had been found about 7 bushels of vegetable matter supposed to have been contained in the stomach. He took some of it to London and had it examined microscopically. It appeared to belong to the white cedar, Thuja occidentalis.